John and Sally Perkins used Rhododendron calendulaceum 'Cherokee' as the seed parent in testing their conjecture that tetraploid deciduous azalea species normally reject pollen from diploid deciduous azaleas. Their test indicated that in all 5 cases where tetraploid pollen was placed on 'Cherokee' large seedpods were produced whereas in all 13 cases where diploid was placed on 'Cherokee' no seedpods were produced. This result was completely consistent with results the Perkins had experienced previously when working with other tetraploid deciduous azaleas as seed parents.

John and Sally Perkins have shown that diploid deciduous azalea do accept pollen from both diploid and tetraploid deciduous azaleas.